Implicit learning procedures have the potential to greatly enhance language training, and yet have received little attention in the aphasia rehabilitation literature. Preliminary evidence of implicit learning ability in individuals with aphasia suggests that this approach could lead to less effortful language rehabilitation strategies, which may be used in combination with established methods of explicit treatment of grammatical ability. The long-term goal of the proposed work is to further the understanding of learning processes in aphasia, and to use that knowledge to engage patients in language learning strategies that will be most beneficial for language recovery. The specific objective of the proposed project is to test an implicit approach to artificial grammar learning in healthy and agrammatic aphasic individuals using a statistical learning paradigm. The central hypothesis is that implicit learning mechanisms, which are effective in deriving grammatical structure from statistical relationships in language, remain intact in individuals with aphasia, and that grammar learning is enhanced when passive language exposure is combined with active practice. The proposed research will be the first to test learning and short-term retention of an artificial phrae structure grammar under implicit learning conditions in individuals with agrammatic aphasia and healthy age-matched adults. Participants in this study will receive repeated passive exposure to the grammar on two consecutive days, and their acquisition and 24-hour retention of the grammatical rules will be evaluated by grammaticality judgment tests. The proposed research will also use the artificial grammar learning task with healthy young adults to test the relative effects of passive exposure to the grammar compared to active practice with feedback and a combination of both approaches. These contributions are significant because they are the first steps toward evaluation of an approach that utilizes patients' retained learning abilities and hence can improve the quality of life of individuals with aphasia.